Wire recorder



May 13, 1952 c, D 2,596,535

WIRE RECORDER Filed Oct. 30, 1948 3 Sheets-Sheet l IN VEN TOR. IE 36 7 Cohn B. Dale May 13, 1952 Filed 001:. 30, 1948 C. B. DALE WIRE RECORDER 3 Sheets-Sheet 2 INVENTOR. Colin B. Dale y 13, 1952 c. B. DALE 2,596,536

WIRE RECORDER Filed 001;. 50, 1948 3 Sheets-Sheet 3 JNVENTOR. Colin .3. Dale Patented May 13, 1952 WIRE RECORDER Colin B. Dale, Harrington, 111., assignor to Webster-Chicago Corporation, Chicago, 111., a corporation of Illinois Application October 30, 1948, Serial No. 57,459

3 Claims.

This invention relates to a sound recording and reproducing mechanism utilizing a magnetizable medium, such as a steel wire, tape, or other material which is capable of being magnetized. Instruments of this type are commonly known as wire recorders, and will be so referred to herein. The term "wire will also be used in a generic sense to include any of the long-length magnetizable mediums such as those already noted.

The wire is regularly wound onto supply spools and, when operated in a wire recorder, is then wound onto a take-up spool, and later rewound back onto the supply spool. In the handling of the supply spools there is always the problem of fastening the outermost exposed end of the wire. If free, it will readily become disarranged, quickly snarled, and irretrievably useless; but if the wire end be secured to the spool, the latter may then be handled without liability of the wire coming loose.

One object of my invention is the provision of an improved means for securing the end portion of the wire which remains free after the remaining wire length has been wound on the spool, so that the wire will not come loose therefrom, and to accomplish this in a way which is inexpensive, without any additional operation, and which is readily separable, when desired. I have found that the attachment to the free wire end of a short leader, perhaps two or three feet in length, consisting of a thread of nylon or other material having like frictional and limp properties, will suffice for all purposes of this invention. This results from the fact that when the wire is fully wound on the spool, a number of turns of the leader are also disposed over the.

outermost convolutions of the wire, and the leader then readily conforms to the surface of the windings of the wire to engage therewith with a degree of limpness and friction which will hold both the wire and the attached leader dependably in place. A spool on which is wound a length of wire having the present leader attached to its outermost end to complete the windings upon the spool may then be handled in any of the usual ways without the wire coming loose or being damaged in any way. This is one of the features of the present invention.

Another object of my invention is the securement of the wire to both the supply and take-up spools in such a way that, at the conclusion of the unwinding operation, either direction, the wire will be shifted from a position which is tangential to one which is radial with respect to the spool, and in so doing to actuate an electric switch by which operation of the wire recorder is stopped. Aifixing of the wire to either spool presents a problem because the wire is so fine that it tends to break or kink if given a sharp bend or if knotted at any place; even if it be tied rather loosely, the wire will bulge and prevent the formation of level windings thereon. By the attachment of a fine limp leader, such as a thread of nylon or the like, it is possible to provide for the wire an inseparable knotted connection with the supply spool and a self-releasing but operative connection with the take-up spool, and to assure, at almost the conclusion of its unwinding movement, a shifting in the wire position from one which is tangential to one which is radial whereby to accomplish a stopping of the recorder mechanism as above noted.

Another object of the invention is the provision of a pair of switches, each having a control arm adjacent the wire, one being located close to the supply spool and the other close to the take-up spool, each switch being operable by shifting of the wire at the conclusion of its unwinding movement. The two switches are in series in the electrical circuit connected with the motor which operates the wire recorder, so that the opening of either switch will act to stop operation of the motor and of the recorder mechanism driven thereby.

Another object of the invention is to provide a position meter or time indicator installed as a separate unit and provided with a pointer actuated by engagement of a friction wheel with the drum of the take-up spool through speed reducing gearing which may be such that the pointer will be moved through 360 with one hour of play or any other selected unit of time.

It is also an object of the invention to provide a graduated disc of paper or other material over which the pointer of the position meter or time indicator moves and which will assist the eye in determining how much play has ensued and how much still remains ahead or unplayed, the disc bein removable from the cover plate with each removal of the supply spool.

A further object of the invention is to provide for the control lever which swings to the right or left a pair of depressible stop buttons located adjacent to and at opposite sides of the control lever, and arranged normally to prevent movement of the control lever in either direction from a mid position; operation of the one or the other of the stop buttons is required to free the control lever for swinging to the right or left, as the case may be. The provision of such stop buttons efiectually prevents a too-fast full movement of the control lever, thereby avoiding any reverse movement of the parts while they are still undergoing a movement in the opposite direction.

A further object of the invention is to arrange the depressible control buttons in position to remain down when either is operated and the control lever is moved to an operative position permitted by such depression of the stop button, so that it will be unnecessary to again operate such stop button to permit the control lever. to be returned to its mid position or to be moved in the opposite direction.

With the above and other objects in view, the

stop buttons at opposite sides of the handle of the control lever;

Fig. 2 is a detail sectional view, taken on line 22 of Fig. 1;

Fig. 3 is a plan view of the position meter partly broken away to exhibit the reduction gearing for rotating the pointer thereof;

Fig. 4 is a detail sectional view, taken on line 5-4 of Fig. 3;

Fig. 5 is a horizontal sectional view looking down from a plane that is immediately below the 4.

cover plate.

Fig. 6 is a detail sectional View, taken on line 6-6 of Fig. 1;

Fig. 7 is a similar view, taken on line l -71 of Fig. 1;

Fig. 8 is a plan view illustrating the position of theparts when one end portion of the wire is in engagement with its associated micro-switch;

Fig. 9 is a similar view illustrating the arrangement of the parts when the other end portion of the wire is in engagement with its associated switch;.and

Fig. 1-0 is a detail wiringdiagram showing the electrical connections which include the operating motor andthe micro-switches.

The wire'w which is wound upon a supply spool S may be provided at its ends with leaders It and I6 secured thereto as by knots H and i8 (see Figs. 8 and 9). Each leader, which may be twoor three feet long, consists of a fine cord or thread of rayon, cotton, or other suitable material having a high degree of limpness and frictional value. The wire is normally extended tangentially between the supply spool Sand a takeup' spool T forming part of a' wire recorder. One end of the wire (or of a leader connected thereto) is extended around the hub l 9 of the supply spool andthen knotted to the wire (or leader) at 2@ to provide a loop 2 i. When unwound to its limit,

the'wire is disposed radially of the spool S, and F adjacent arms 22 and 23 which upstand from electric switches 24 and 25. The advantage of an attached leader of rayon or the like is twofold: (1) it is far more flexible and pliable than is the wire, and so may be tied or formed into a knot which will be stronger and smaller, and (2) it tends to stay put when it completes the windings upon the supply spool, thereby obviating the necessity of buryin or tucking the end portion of the wire between other turns or convolutions in order to prevent unwinding of the wire durin handling of the spool.

' The wire recorder may beprovided with a cover plate 21 which is appropriately recessed to accommodate the wire supply spool S, a pickup head H, and the wire take-up spool T. The switches 24 and 25 are desirably of short operating movement, such as micro-switches, and are arranged in series in a circuit 28 including a motor 29 (see Fig. 10) and when either microswitch is moved from its closed position the circult is opened and the motor is deenergized. In operation, .the wire advances from the supply spool S to the take-up 'spool T with the two micro-switches in closed position. At the conclusion of the wire feed the wire (or leader) loop 21 surrounding the spool hub l9 halts further outward movement of the wire which thenstands in a radial position relative to the spool. This change in the wire position causes the switch arm 22 to be-engaged, thereby cutting oh? the motor. During the brief interval that the supply spool is decelerating to a stop, it is free, if necessary, to slip around a chuck C carried by a vertical shaft 32 that is journaled in suitable. bearings (not shown); at the same time the loop 2| may or may not also be slipping upon the spool hub-- this is an unimportant detail. The wire end portion '(or leader attached thereto) does remain stationary and in a radial position relative to the supply spool which, if checked with sufficient force, wi1l slip upon the chuck which drives it through a frictional connection as will hereinafter appear. 7 r

The chuck C (see Fig. 6) is formed with a depending drum 33 arranged concentric with the" shaft 32. For operating the chuck I provide the motor 29 (not shown except as indicated in the wiring diagram) whose shaft ,35 projects upwardly through an opening in a base plate 36. A friction wheel ii is fastened on the shaft 35 near its top end. The tread of the friction wheel 31. is adapted for drivingengagement with the drum 33 of the chuck C to rotate the supply spool S carried thereby in a counter-clockwise direction, as viewed in Fig. 5. When a control switch operated by the handle 38 is ineitherits run position or in its stop (neutral) position, the fricg tion wheel 3? is carried out of contact with the chuck drum 33. The motor may be mounted in. any suitable manner to permit the upper end of the shaft to be shifted laterally. 'Since the details of the motor mount form no part of this invention, any further description thereof is unnecessary.

Rising centrally from the chuck C is a hub 49 whose, peripheral walls il are. concentric with the shaft 32. The hub is provided with an outwardly extending annular base 42 whereon the spool S is gravity supported, the frictional engagement therebetween acting as the driving connection for the chuck. A convex cap 43 is secured to the top end of the shaft 32, the peripheral edge of the cap being downturned for seating in aperipheral groove of the hub.. Theco'n s'truction just described is one which facilitates the mounting and removal of successive supply spools S, since it is not necessary to accurately align the axial opening through the spool with the hub 40, nor to assemble the spool on the hub in any particular angular relation. When fitted operatively onto the chuck hub the entire surface area of one end of the spool is in frictional engagement with its base 42.

The wire take-up spool T is provided with a bottom end wall 44 having a center hole and also a circular shoulder 45 near its periphery. This spool is carried on the top end of a cylindrical drum 46 secured to the upper end of a vertical shaft 4'! which is journaled in suitable bearings. When the take-up spool is positioned in place, theshaft 4'! will extend through the center hole of its bottom end wall 44 whose peripheral edge substantially engages the circular shoulder 45. An off-center pin 48 upstanding from the drum is adapted to enter any one of several coradial holes 49 in the wall 44 to establish a driving connection between the drum and spool. The takeup spool is accordingly maintained in centered relation with the drum by which it is driven, and its mounting thereon is such that it may be freely removed therefrom whenever desired.

Horizontally aligned with the drum is a friction wheel 50 which functions as an idler between the motor shaft 35 and the take-up spool T. The idler wheel 50 is rotatably mounted on a vertical stub shaft carried by an arm 52 which is fulcrumed on a pivot 53 that is fastened to the base plate 36. When the control switch of the machine is in running position the upper end of the motor shaft 35 is shifted over to engage the tread of the idler wheel 50 to urge the latter against the drum 45 of the take-up spool T. Because of the large diameter of this drum relative to that of the motor shaft 35, the take-up spool T rotates relatively slowly, when driven, the wire speed under these conditions being about one-seventh of that which obtains when the chuck C is being driven by the friction wheel 37. The driving connections thus established between the motor and the drum 4% are, in effect, positive and non-slipping.

A circular cover plate 54 on the take-up spool provides therefor an upper flange wherein is formed an edge notch 55. The leading end of the wire w (or leader affixed thereto) is extended from the supply spool 5 partially around the recording head H and then into the notch 55 for insertion beneath a latching finger 55 which bears on the upper surface of the cover plate 54.

The head H houses the coils for recording sound magnetically on the wire 20 and for picking up the acoustic signal from the wire, depending upon whether the instrument is being operated to record or reproduce the sound. The head H also contains an erasing coil for demagnetizing the wire to clear it of any previous recording when the instrument is being operated for recording purposes, as is familiar to those skilled in the art. Inasmuch these portions of the apparatus are conventional, a detailed olescription thereof is not included herein. A notch 57 is provided in the head, as usual, for reception of the wire w by which it is also guided in its movements between the supply and takeup spools. The head H may be mounted to reciprocate slowly in a vertical direction so as to assure level winding of the wire on whichever spool it is to be received.

The wire is also maintained taut while both moving and while stationary in the machine, and is prevented from over-running on either spool so as to prevent its fouling or snarling. To this end, there is provided a dual braking mechanism operable through manipulation of the control handle 38 for selectively braking the chuck C and the take-up spool T. The braking means includes brake arms 65 and 61 pivotally mounted on the base plate 35 and associated, respectively, with the chuck C and the take-up spool T. The brake arm carries a shoe 52 which consists of a pad of friction material adapted to engage the drum 33 of the chuck C when the brake shoe 52 is released to the action of a spring 63. A lever 65 having a tongue and slot connection with the brake arm (is is pivoted on the base plate 316. A similar lever 51' pivoted on the base plate is also in a tongue and slot connection with the second brake arm 5!. A spring 53 tends to urge the brake arm 5! toward the drum 45 of the take-up spool T for bringing a shoe is on this arm into engagement therewith.

The control lever 38 includes in its structure a cylindrical rotor 12 which carries upper and lower coaxial brake control cams it and 14, respectively. The brake control levers and 5? are provided, respectively, with cam followers 35 and it; that cooperate with the control cams 'itl and it. Springs ii and 13 act upon the cam followers to urge them toward the periphcries of the cams is and 13, respectively. Projecting from the rotor i2 is a key as that fits in a slot of corresponding size in the cam 14 and in an elongated arcuate slot 8| in the cam '53 so as to lock with the former for concurrent movement, but with the latter for a lagging movement. The brake control cams l3 and '54 may assume four different positions relative to the cam followers '55 and it, depending upon the setting of the control handle 33.

5 illustrates the parts in the stop position, the control handle being indicated by the dot and dash line 35'.

Considering first the operation when the control handle is in its run position, the follower 75 then rests on a step a of the cam it, while the cam follower it rides on a high portion 19 of the same cam. As a result of this disposition of the cams and cam followers, the lever 51 and brake arm M are rocked to an extent sufiicient to withdraw the brake shoe 73 from contact with the drum 4.5 of the take-up spool T. The lever and brake arm til are then. so positioned that the brake shoe E2 is applied only lightly to the drum 33 of the supply spool chuck C. The movement of the control handle 33 to the left, for setting the control switch in run position, is limited by engagement of a lug on the cam 14 with a stop i5 projecting upwardly from the base plate 36. The control lever 38 is impositively held in this position by the cam followers 75 and it.

From the foregoing description it will be apparent that when the machine is being used to record or reproduce, the chuck C from whose supply spool the wire to is being drawn is braked only lightly. Hence, if the operation of the motor should be interrupted while the control switch is still set in running position, the momentum of the chuck C and its wire supply spool S is checked so that over-running is prevented. The take-up spool T need not then be braked since the motor is coupled thereto for driving purposes.

,;j 'l-o;stop the operation of thewire'handling 3,; means, the, control handle 381s moved into its :neutral or stop position as shown in Fig. 5. ,zr-Assuming that the handle has previously been in runf position, it will then approach the neu- 'tral'position from the left, as viewed in Fig. 1. :Because of the lost-motion connection between 1 the rotor 12 and the cam '53, the latter, is advanced counter-clockwise (as viewedin Fig. 5); or, in

"other words, the cam is lags the cam is by the :amount oflost motion which occurs as the lug cc travels lengthwise within the arcuate slot 8i. As the'cam M is advanced into the position shown in'Fig. 5; the follower l5 rides off the high portion b of this cam and onto a somewhat lower portionc, which forms a dwell on the cam 73. The terms high and low in'this' connection refer to large and small radii, respectively. The

cam follower 15 rides oh the step a and drops into a relief or dwell d on the cam l3. Dueto friction there is some tendency for the cam 73 to be carried along by the cam it, but any such movement is checked when engagement takes place between the cam follower iii and a slight rise e at the end of the dwell c, and between the cam follower l5 and" a rise f on the '53,. The friction between the cams l3 and Hi can be made sufiiciently small, such as by the use of lubricant, so that the cam 73 cannot be moved to'cvercome the spring pressure oi the followers l5 and 55 unless positively actuated.

The result of disposing the parts as shown in Fig. 5 is that the brake arm til, being entirely released to the action of the springs and ii,

advances the brake shoe 62 heavily against the chuck drum 33, while the brake shoe in is applied lightly to the drum iii of the take-up spool T. In this operation the wire handling means is to be stopped after a run for recording or reproducing purposes. stopped abruptly so as to prevent over-running of the supply spool S from which the wire is drawn. At the same time the take-up spool T, being slightly braked, has no'tendency to reverse .or spin when the wire is stopped. When the control handle 38 is moved into its rewind position, the parts oi the braking mechanism are differently, disposed. The cam follower 15 then rides onto a high portion g oithe cam i l, causing the brake shoe 62 to disengage from the chuck drum 33 which is then being driven counter-clockwise to rewind the wire upon the supply spool S. The cam it, being positively V actuated by the key 35), is moved counter-clockwise so that the cam follower Ed rides oh the rise'b and ontoa step it on the cam it. This causes the brake shoe E3 to be applied'lightly against the drum iii of the take-up spool T,

thereby to maintain the wire to under only slight tension as it is drawn oii the take-up spool T, and to prevent any over-spin of the take-up spool The chuck C, therefore, is

i y ,t vtne1 s z on cammcenseque the b ake s e l o ra i g-9n. he tak -141151 T is ap l d h v ly while he ra e 11 62 which operates on the supply chuck Qis applied only-lightly; These brake settings (seeFig.

mare-thereverse of those-which obtained when thecontrol handle 33 was moved fromffrun position to the stop position. 7

The latching finger 56 isformed ontheend of an arm 85, which is mounted on thennder side of" the cover 54. radially thereof, the finger 56 being extendedupwardly through anaperture in the cover. Upward, pressure is exerted on the arm 35 by a compression spring 86 disposed around a headed pin orscrew .81, that extends through the cover 54 and the arm 85- to depend therebelow; The arm 5 pivots about aiulcrum =point 88 so that the spring 36 is effective tourge the fingerfit downwardly. against thecover 54.

A button 90 on the end of the arm 35 projects through acentral opening in the cover so as to be exposed to receive pressure by which the latching. finger 55 may be raised. With release of pressure on this button. the end portion of the wire to (or leaderattached thereto) isfirmly but releasably clamped to the take-up spool, {If under pressure ofv the spring 3% acting upon the latching finger 55.

To rewind the wire w onto, thesupply, spool S, it is necessary that bothmicro-switches M and 25 be closed and that the control handle 33 be moved to the right too rewind position, and be maintained there until all of the .wire isqdrawn back onto the supply spool S.- The rewinding operation. takes place veryrapidly and nearv the conclusion of this movement'the .trailingwire end (or attached leader) is pulled free of the latching ringer fiesoas todisconnect from. the 1 take-up spool T. In the brief moment, attending coiled position around thesupplyspoolS.

such circumstances there need be noiucking of 7 its separation from the take-up spool, the wire (or attached leader it) willswing inwardly from a tangential to a, radial position, thereby pushing inwardly the arm 23 to open the micro switch 25 andstop the motor. If the trailing end of the wire'carry a leader it, the latter near the conclusion of its movement will be woundupon and coiled around the supply spool -S whe re i t overlies the outer convolutionsof the ;wire windings thereon, and the frictional engagement of the leader with the adjacentwindingsgwill, without other means; act to rnaintain the leader in its In the coils or'convolutions of the leaderinxbetween if slack should develop in the wire. The move merit of the control lever 33 into the stop position may be limited by engagement or" a lug a;

on the camlfi with the stop is.

To terminate or interrupt the rewind Operation, the control handle 38 is moved into the stop or neutral position wherein the cams i3 and i i are caused to assume still another position. Here q-the cam 13 is moved with the cam i i until the cam follower 75, which has moved off the high -porti0n g of the cam M and onto the inter- .mediate dwell cl of the cam 13, engages the slight ,1 rise 1 at the end of this dwell, and the follower 1" 1.5, which hasmoved oi? the step It and onto the low portion 0 of the cam '73, is disposed inwproxother turns or convolutions in orderito secure the important that travel of the wire cease at mecisely the moment when the wire reaches the radial position relative to the supply spool; if it is carried past the radial point the resistance will continue to mount so as to assure a gradual but complete stoppage of wire trave1 very quickly. In many cases the wire which is looped around the hub of the supply spool will tend to slip thereupon-if the spool-continue to 'rotate after the wire or attached leader has reached the radial position. In no event, however, is there any abrupt stoppage of the wire in its travel toward the take-up spool with consequent overstraining of the wire or injury to any of the parts in the mechanism.

When the wire is rewound back onto the supply spool, it is free to disengage itself from the take-up spool at the conclusion of its movement. This comes about from the fact that the wire or attached leader at the trailing end is releasably connected to the take-up spool. At about the conclusion of its unwinding movement the edge notch 55 which serves as an open guide will be facing toward the head H so that the wire (or attached leader) at the trailing end will be extending outwardly from the latching finger 56 in substantially a radial direction. At this point the frictional resistance imposed by the edge notch 55 and latching finger 56 Will be reduced to a minimum so that the wire (or attached leader) will then be enabled to slip outwardly therefrom and disengage itself from the take-up spool T. This is important because the wire is not subjected to any severe strain at the conclusion of the unwinding operation from the take-up spool which proceeds much more rapidly than does the wire movement when traveling in the opposite clirection.

With the supply spool the wire connection is fast, whereas with the take-up spool the wire connection is releasable; however, the driving connection with the supply spool is frictional, with capacity for slipping in case of overload, whereas with the take-up spool the driving connection is positive. This is an advantageous arrangement in conjunction with the two wire-operated switches which are series-connected with the motor. at the conclusion of wire movement outwardly from the supply spool, then the latter is free to slip on its chuck until the driving connections are at rest. Likewise, if the take-up spool should tend to over-run at the conclusion of wire movement outwardly therefrom, no harm will result because of the releasable connection which frees the Wire therefrom at the conclusion of the rewind operation. Either or both of these safety features may be employed to safeguard the wire and associated parts against damage. Halting of the wire movement by opening of a motor-controlling switch in the manner herein explained at length does not involve any operation of the brake system which is controlled soie'y by the control handle 33.

In the operation of automatically stopping the motor, the presence of a leader at one or both ends of the wire is not at all necessarv, although rather desirable from several standpoints. Accordingly, when reference herein is made to the wire, in connection with the automatic stop ping of the motor, it should be understood that this term includes optionally a leader at one or both ends of the wire.

The control handle which swings to the right or left and also to a mid position, is limited in its mid position by a pair of adiacent stop buttons 92 and 93 extending upwardly through openings Qt and 95 in the cover plate 2i, and urged upwardly by coil springs 38 and ill and limited in their upward movement by annu ar collars 98 and 59, preferably formed integral with the stop buttons. These buttons and the springs are mounted in an approximately U-shaped bracket it! composed of a horizontal bottom por Should the motor fail to stop promptly tion and vertical side portions having their upper terminals Hi2 extended laterally and riveted or otherwise secured in a fixed position beneath the cover plate 2?. The stop buttons or and 93 are slightly reduced in diameter below the collars 98 and 99 to receive the coil springs 95 and ill which are interposed between the collars and the horizontal bottom portion of the bracket It i. The stop buttons are rovided at their lower portions with stems I03 and me which extend through and are slidable in apertures of the horizontal bottom portion of the bracket. The upper portions of the stop buttons project above the base plate a sufficient distance to form stops for confiining the control handle 31% in its neutral or stop position. When it is desired to move the control handle to run position, it is necessary first to depress the stop button s2 before the control handle 38 can be swung to the left. When so moved, the control handle lies above the stop button 92 and maintains the same in a depressed position. When the control handle is returned to a mid position, it is unnecessary to operate the stop button 52 manually, and the handle is free at all times to move to such mid position without interference.

When the control handle has been moved to its mid position from over the stop button 92, the latter is automatically returned to its projeoting position by the coil spring 96. To move the control handle to the right from either a run position or a mid or neutral position, it is necessary todepress the right hand stop button 93, and in this movement the control handle 38 is carried to a position thereover. The purpose of these two buttons is to prevent a too-fast full movement of the control lever from a run position to a rewind position or from a rewind position to a run position, thereby avoiding any reverse movement of the parts while they may still be undergoing a movement in the opposite direction. When the control handle is moved from rewind position to neutral position it passes off from over the stop button 93, the latter then being returned to its projecting position by the coil spring 9?.

The wire recorder is provided with a position meter or time indicator which may be installed as a separate unit. It comprises in its construction upper and lower plates I66 and I01 spaced apart and connected by posts I08 to form a framework for the support of reduction gearing consisting of a plurality of gears I59 and pinions iid. The reduction gearing greatly reduces the motion that is communicated from a friction wheel H2, in engagement with the drum it of the take-up spool T, to a pointer l M located above the cover plate 2?. The friction wheel H2, which is mounted on a vertical shaft H5, is provided with a peripheral tread of resilient material adapted to friotionally engage the drum The pointer H4 is provided at its inner end with a cylindrical sleeve II"! which frictionally engages a cylindrical hub extension H8 of one of the gears its. This gear and hub extension I Hi thereof are mounted on a stud I23 rigid with and extending upwardly from the upper plate Hit, as clearly illustrated in Fig. 4 of the drawings. The hub extension I i8 and its associated gear are retained in position on the stud by a screw 62] which is tapped into the stud I20. The head of the screw extends over and engages the upper end of the hub extension I Hi and l1 removably retains the same on the stud. The head of the screw is housed within the sleeve 1 ll of the pointer which may be readily removed from the hub extension topermit a graduated record dial 123 consisting'of a disc of paper or other suitable material to be placed on :and removed fromthe cover plate. 'The record dial chosen unit of time. The graduations on the record dial will assist the eye in determining approximatelyhow much play'has ensued, and how much of the wire of the supply spool remains unplayed. The dial may be removed from the cover plate with each removal of the supply spool and placed therewith as an indication of the .length of the recorded matter that may have been imposed on the wire, or the length of play and various other pencil notations may be made on the record dial for information purposes.

The position meter is pivotally mounted for removal upon a stud I21 which projects upwardly from the base plate 36 in axial alignment with the cylindrical hub extension I I8, and a spring I28 is provided which normally swings the vfree end of the unit whereon the friction wheel H2 is carried toward the drum 46 of the take-up spool 'I so as to assurea driving connection therebetween.

I,.claim:

.1. ,In a wire recorderoi the type which utilizes motor-driven supply and take-upspools between I which a wire is connected releasably to one of them and arranged .to be drawn through a fixed .path between the spools tangential to both of them -'during-unwinding and :winding of the wire on the spools, a motor controlling switch adjacent the one spool to which the wire is releasably connected having operating means proximate said wire, and means on said one spool associated with :said wire and automatically operable substantially at the conclusion of the unwinding of the :wire from said one spool and substantially concurrently with engagement of the wire with said operating means to release the wire upon de-energization of the motor, thereby permitting winding ofthe wire'end on the other spool, said means comprising an arm resiliently pivotally carried by one of the side covers of said one spool,

said arm having a latching finger resiliently maintained in engagement with said cover for releasably resiliently clamping the wire end to said cover. 1

2. In a wire'recorder of the type whichutilizes motor-driven supply and take-up spools between which a wire is connected releasably to one of them and arranged to be drawn through a fixed path between the spools tangential to both of them during unwinding and winding of the wire on the spools, a motor controlling switch adjacent the one spool to which the wire is releasably connected having operating means proximate said wire, and means on said one spool'associated with said wire and automatically operable substanman at the conclusion f the unwinding came wire from said one spool and substantially'concurrently with engagement of the Wire with said operating means to release the wire upondeener gization of the-motor, thereby permitting winding of the wire end on the other spool, said one spool having one of the flanges thereof provided with a notch for receptionof the end of the. wire, said means comprising an arm resiliently pivotally carried by one of the side-covers of saidone-spool,

said arm. having a latching finger resiliently maintained in engagement with said cover for releasably clamping the free endof the wire extendingradially inwardly'irom said notch.

3. In a wire recorder or the type which utilizes motor-driven supply and take-up spools between which a wire is connected releasably to one of them and arranged to be drawn through a fixed path between the spools 'tangential'to both of them during unwinding and winding of the wire on the spools, amotor controlling switch adjacent the one spool to which the Wire is releasably connected having operating means proximate said wire, and, means onsaid one spool associated With said wire and automatically operable substantially at the conclusion of the unwinding of the wire from said onespool and substantially concurrently with engagement of the wire with said operating means to release the wire upon de-energization oi the motor, thereby permitting winding of the wire end on the other spool, said one spool having-oneoi the flanges thereof provided with a notch for reception of the end of the wire, said means comprising an arm resiliently pivotally carried by one of the side covers of said on spool, said arm having a latching finger resiliently maintained in engagement with said cover for releasably clamping the free end of the wire extending radially inwardly from said notch, said arm having a fulcrum point bearing'against said cover for pivoting movement thereabout, said arm-being provided with a-button'at the end thereof remote from said latching finger and exteriorly of said cover for manual disengagement of sa d latching finger from said cover.

COLIN B. 'DALE.

REFERENCES CITED UNITED STATES PATENTS Number Name Date 1,655,297 Thornton Jan. 3, 1928 1,886,856 Warwick Nov. 8, 1932 1,895,244 MeyenC-aus'et a1. .Jan. 24, 1933 1,998,208 .Still Apr. 6, 1935 2,369,017 Camras Feb. 6, 1945 2,381,036 Camras Aug. 7, 1945 2,401,632 "Greenleaf June 4, 1946 2,415,133 Heineman- Feb. 4, 1947 2,460,190 Petroff Jan.f25, 1949 2,463,001 Shrader Mar. 1,1949 2,481,004 Dale "Sept. 6, 1949 2,489,735 Zancan Nov. 29, 1949 2,519,245 Greenleaf et al Aug. '15, 1950 

